mirror of https://github.com/status-im/go-waku.git
wakuv1 envelope format
This commit is contained in:
Richard Ramos
parent
65fc98f450
commit
100a26f49c
|
|
@ -5,11 +5,14 @@ import (
|
|||
"crypto/cipher"
|
||||
"crypto/ecdsa"
|
||||
crand "crypto/rand"
|
||||
"encoding/binary"
|
||||
"fmt"
|
||||
mrand "math/rand"
|
||||
|
||||
"errors"
|
||||
"strconv"
|
||||
|
||||
"github.com/ethereum/go-ethereum/crypto"
|
||||
"github.com/ethereum/go-ethereum/crypto/ecies"
|
||||
"github.com/status-im/go-waku/waku/v2/protocol"
|
||||
)
|
||||
|
|
@ -22,16 +25,122 @@ const (
|
|||
None KeyKind = "None"
|
||||
)
|
||||
|
||||
type KeyInfo struct {
|
||||
Kind KeyKind
|
||||
SymKey []byte
|
||||
PrivKey ecdsa.PrivateKey
|
||||
// The message to encode
|
||||
type Payload struct {
|
||||
Data []byte // Raw message payload
|
||||
Padding []byte // Used to align data size, since data size alone might reveal important metainformation.
|
||||
Key *KeyInfo // Contains the type of encryption to apply and the private key to use for signing the message
|
||||
}
|
||||
|
||||
// NOTICE: Extracted from status-go
|
||||
// The decoded payload of a received message.
|
||||
type DecodedPayload struct {
|
||||
Data []byte // Decoded message payload
|
||||
Padding []byte // Used to align data size, since data size alone might reveal important metainformation.
|
||||
PubKey *ecdsa.PublicKey // The public key that signed the payload
|
||||
Signature []byte
|
||||
}
|
||||
|
||||
type KeyInfo struct {
|
||||
Kind KeyKind // Indicates the type of encryption to use
|
||||
SymKey []byte // If the encryption is Symmetric, a Symmetric key must be specified
|
||||
PubKey ecdsa.PublicKey // If the encryption is Asymmetric, the public key of the message receptor must be specified
|
||||
PrivKey *ecdsa.PrivateKey // Set a privkey if the message requires a signature
|
||||
|
||||
}
|
||||
|
||||
func (payload Payload) Encode(version uint32) ([]byte, error) {
|
||||
switch version {
|
||||
case 0:
|
||||
return payload.Data, nil
|
||||
case 1:
|
||||
data, err := payload.v1Data()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
if payload.Key.PrivKey != nil {
|
||||
data, err = sign(data, *payload.Key.PrivKey)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
}
|
||||
|
||||
switch payload.Key.Kind {
|
||||
case Symmetric:
|
||||
encoded, err := encryptSymmetric(data, payload.Key.SymKey)
|
||||
if err != nil {
|
||||
return nil, errors.New("Couldn't encrypt using symmetric key")
|
||||
} else {
|
||||
return encoded, nil
|
||||
}
|
||||
case Asymmetric:
|
||||
encoded, err := encryptAsymmetric(data, &payload.Key.PubKey)
|
||||
if err != nil {
|
||||
return nil, errors.New("Couldn't encrypt using asymmetric key")
|
||||
} else {
|
||||
return encoded, nil
|
||||
}
|
||||
case None:
|
||||
return nil, errors.New("Non supported KeyKind")
|
||||
}
|
||||
}
|
||||
return nil, errors.New("Unsupported WakuMessage version")
|
||||
}
|
||||
|
||||
func DecodePayload(message *protocol.WakuMessage, keyInfo *KeyInfo) (*DecodedPayload, error) {
|
||||
switch *message.Version {
|
||||
case uint32(0):
|
||||
return &DecodedPayload{Data: message.Payload}, nil
|
||||
case uint32(1):
|
||||
switch keyInfo.Kind {
|
||||
case Symmetric:
|
||||
if keyInfo.SymKey == nil {
|
||||
return nil, errors.New("Symmetric key is required")
|
||||
}
|
||||
fmt.Println("AAA")
|
||||
|
||||
decodedData, err := decryptSymmetric(message.Payload, keyInfo.SymKey)
|
||||
if err != nil {
|
||||
return nil, errors.New("Couldn't decrypt using symmetric key")
|
||||
}
|
||||
|
||||
decodedPayload, err := validateAndParse(decodedData)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
fmt.Println("AAA")
|
||||
|
||||
return decodedPayload, nil
|
||||
case Asymmetric:
|
||||
if keyInfo.PrivKey == nil {
|
||||
return nil, errors.New("Private key is required")
|
||||
}
|
||||
|
||||
decodedData, err := decryptAsymmetric(message.Payload, keyInfo.PrivKey)
|
||||
if err != nil {
|
||||
return nil, errors.New("Couldn't decrypt using asymmetric key")
|
||||
}
|
||||
|
||||
decodedPayload, err := validateAndParse(decodedData)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
return decodedPayload, nil
|
||||
case None:
|
||||
return nil, errors.New("Non supported KeyKind")
|
||||
}
|
||||
}
|
||||
return nil, errors.New("Unsupported WakuMessage version")
|
||||
}
|
||||
|
||||
const aesNonceLength = 12
|
||||
const aesKeyLength = 32
|
||||
const signatureFlag = byte(4)
|
||||
const flagsLength = 1
|
||||
const padSizeLimit = 256 // just an arbitrary number, could be changed without breaking the protocol
|
||||
const signatureLength = 65
|
||||
const sizeMask = byte(3)
|
||||
|
||||
// Decrypts a message with a topic key, using AES-GCM-256.
|
||||
// nonce size should be 12 bytes (see cipher.gcmStandardNonceSize).
|
||||
|
|
@ -62,49 +171,23 @@ func decryptSymmetric(payload []byte, key []byte) ([]byte, error) {
|
|||
// Decrypts an encrypted payload with a private key.
|
||||
func decryptAsymmetric(payload []byte, key *ecdsa.PrivateKey) ([]byte, error) {
|
||||
decrypted, err := ecies.ImportECDSA(key).Decrypt(payload, nil, nil)
|
||||
if err == nil {
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return decrypted, err
|
||||
}
|
||||
|
||||
func DecodePayload(message *protocol.WakuMessage, keyInfo *KeyInfo) ([]byte, error) {
|
||||
switch *message.Version {
|
||||
case uint32(0):
|
||||
return message.Payload, nil
|
||||
case uint32(1):
|
||||
switch keyInfo.Kind {
|
||||
case Symmetric:
|
||||
decoded, err := decryptSymmetric(message.Payload, keyInfo.SymKey)
|
||||
if err != nil {
|
||||
return nil, errors.New("Couldn't decrypt using symmetric key")
|
||||
} else {
|
||||
return decoded, nil
|
||||
}
|
||||
case Asymmetric:
|
||||
decoded, err := decryptAsymmetric(message.Payload, &keyInfo.PrivKey)
|
||||
if err != nil {
|
||||
return nil, errors.New("Couldn't decrypt using asymmetric key")
|
||||
} else {
|
||||
return decoded, nil
|
||||
}
|
||||
case None:
|
||||
return nil, errors.New("Non supported KeyKind")
|
||||
}
|
||||
}
|
||||
return nil, errors.New("Unsupported WakuMessage version")
|
||||
}
|
||||
|
||||
// ValidatePublicKey checks the format of the given public key.
|
||||
func ValidatePublicKey(k *ecdsa.PublicKey) bool {
|
||||
func validatePublicKey(k *ecdsa.PublicKey) bool {
|
||||
return k != nil && k.X != nil && k.Y != nil && k.X.Sign() != 0 && k.Y.Sign() != 0
|
||||
}
|
||||
|
||||
// Encrypts and returns with a public key.
|
||||
func encryptAsymmetric(rawPayload []byte, key *ecdsa.PublicKey) ([]byte, error) {
|
||||
if !ValidatePublicKey(key) {
|
||||
if !validatePublicKey(key) {
|
||||
return nil, errors.New("invalid public key provided for asymmetric encryption")
|
||||
}
|
||||
|
||||
encrypted, err := ecies.Encrypt(crand.Reader, ecies.ImportECDSAPublic(key), rawPayload, nil, nil)
|
||||
if err == nil {
|
||||
return encrypted, nil
|
||||
|
|
@ -187,29 +270,154 @@ func generateSecureRandomData(length int) ([]byte, error) {
|
|||
return res, nil
|
||||
}
|
||||
|
||||
func Encode(rawPayload []byte, keyInfo *KeyInfo, version uint32) ([]byte, error) {
|
||||
switch version {
|
||||
case 0:
|
||||
return rawPayload, nil
|
||||
case 1:
|
||||
switch keyInfo.Kind {
|
||||
case Symmetric:
|
||||
encoded, err := encryptSymmetric(rawPayload, keyInfo.SymKey)
|
||||
if err != nil {
|
||||
return nil, errors.New("Couldn't encrypt using symmetric key")
|
||||
} else {
|
||||
return encoded, nil
|
||||
}
|
||||
case Asymmetric:
|
||||
encoded, err := encryptAsymmetric(rawPayload, &keyInfo.PrivKey.PublicKey)
|
||||
if err != nil {
|
||||
return nil, errors.New("Couldn't encrypt using asymmetric key")
|
||||
} else {
|
||||
return encoded, nil
|
||||
}
|
||||
case None:
|
||||
return nil, errors.New("Non supported KeyKind")
|
||||
func isMessageSigned(flags byte) bool {
|
||||
return (flags & signatureFlag) != 0
|
||||
}
|
||||
|
||||
// sign calculates the cryptographic signature for the message,
|
||||
// also setting the sign flag.
|
||||
func sign(data []byte, privKey ecdsa.PrivateKey) ([]byte, error) {
|
||||
result := make([]byte, len(data))
|
||||
copy(result, data)
|
||||
|
||||
if isMessageSigned(result[0]) {
|
||||
// this should not happen, but no reason to panic
|
||||
return result, nil
|
||||
}
|
||||
|
||||
result[0] |= signatureFlag // it is important to set this flag before signing
|
||||
hash := crypto.Keccak256(result)
|
||||
signature, err := crypto.Sign(hash, &privKey)
|
||||
|
||||
if err != nil {
|
||||
result[0] &= (0xFF ^ signatureFlag) // clear the flag
|
||||
return nil, err
|
||||
}
|
||||
result = append(result, signature...)
|
||||
|
||||
return result, nil
|
||||
}
|
||||
|
||||
func (payload Payload) v1Data() ([]byte, error) {
|
||||
const payloadSizeFieldMaxSize = 4
|
||||
result := make([]byte, 1, flagsLength+payloadSizeFieldMaxSize+len(payload.Data)+len(payload.Padding)+signatureLength+padSizeLimit)
|
||||
result[0] = 0 // set all the flags to zero
|
||||
result = payload.addPayloadSizeField(result)
|
||||
result = append(result, payload.Data...)
|
||||
result, err := payload.appendPadding(result)
|
||||
return result, err
|
||||
}
|
||||
|
||||
// addPayloadSizeField appends the auxiliary field containing the size of payload
|
||||
func (payload Payload) addPayloadSizeField(input []byte) []byte {
|
||||
fieldSize := getSizeOfPayloadSizeField(payload.Data)
|
||||
field := make([]byte, 4)
|
||||
binary.LittleEndian.PutUint32(field, uint32(len(payload.Data)))
|
||||
field = field[:fieldSize]
|
||||
result := append(input, field...)
|
||||
result[0] |= byte(fieldSize)
|
||||
return result
|
||||
}
|
||||
|
||||
// getSizeOfPayloadSizeField returns the number of bytes necessary to encode the size of payload
|
||||
func getSizeOfPayloadSizeField(payload []byte) int {
|
||||
s := 1
|
||||
for i := len(payload); i >= 256; i /= 256 {
|
||||
s++
|
||||
}
|
||||
return s
|
||||
}
|
||||
|
||||
// appendPadding appends the padding specified in params.
|
||||
// If no padding is provided in params, then random padding is generated.
|
||||
func (payload Payload) appendPadding(input []byte) ([]byte, error) {
|
||||
if len(payload.Padding) != 0 {
|
||||
// padding data was provided by the Dapp, just use it as is
|
||||
result := append(input, payload.Padding...)
|
||||
return result, nil
|
||||
}
|
||||
|
||||
rawSize := flagsLength + getSizeOfPayloadSizeField(payload.Data) + len(payload.Data)
|
||||
if payload.Key.PrivKey != nil {
|
||||
rawSize += signatureLength
|
||||
}
|
||||
odd := rawSize % padSizeLimit
|
||||
paddingSize := padSizeLimit - odd
|
||||
pad := make([]byte, paddingSize)
|
||||
_, err := crand.Read(pad)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
if !validateDataIntegrity(pad, paddingSize) {
|
||||
return nil, errors.New("failed to generate random padding of size " + strconv.Itoa(paddingSize))
|
||||
}
|
||||
result := append(input, pad...)
|
||||
return result, nil
|
||||
}
|
||||
|
||||
func validateAndParse(input []byte) (*DecodedPayload, error) {
|
||||
end := len(input)
|
||||
if end < 1 {
|
||||
return nil, errors.New("invalid message length")
|
||||
}
|
||||
|
||||
msg := new(DecodedPayload)
|
||||
|
||||
if isMessageSigned(input[0]) {
|
||||
end -= signatureLength
|
||||
if end <= 1 {
|
||||
return nil, errors.New("invalid message length")
|
||||
}
|
||||
msg.Signature = input[end : end+signatureLength]
|
||||
|
||||
var err error
|
||||
msg.PubKey, err = msg.sigToPubKey(input)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
}
|
||||
return nil, errors.New("Unsupported WakuMessage version")
|
||||
|
||||
beg := 1
|
||||
payloadSize := 0
|
||||
sizeOfPayloadSizeField := int(input[0] & sizeMask) // number of bytes indicating the size of payload
|
||||
|
||||
if sizeOfPayloadSizeField != 0 {
|
||||
if end < beg+sizeOfPayloadSizeField {
|
||||
return nil, errors.New("invalid message length")
|
||||
}
|
||||
payloadSize = int(bytesToUintLittleEndian(input[beg : beg+sizeOfPayloadSizeField]))
|
||||
beg += sizeOfPayloadSizeField
|
||||
if beg+payloadSize > end {
|
||||
return nil, errors.New("invalid message length")
|
||||
}
|
||||
msg.Data = input[beg : beg+payloadSize]
|
||||
}
|
||||
|
||||
beg += payloadSize
|
||||
msg.Padding = input[beg:end]
|
||||
|
||||
return msg, nil
|
||||
}
|
||||
|
||||
// SigToPubKey returns the public key associated to the message's
|
||||
// signature.
|
||||
func (p *DecodedPayload) sigToPubKey(input []byte) (*ecdsa.PublicKey, error) {
|
||||
defer func() { _ = recover() }() // in case of invalid signature
|
||||
hash := crypto.Keccak256(input[0 : len(input)-signatureLength])
|
||||
pub, err := crypto.SigToPub(hash, p.Signature)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
return pub, nil
|
||||
}
|
||||
|
||||
// bytesToUintLittleEndian converts the slice to 64-bit unsigned integer.
|
||||
func bytesToUintLittleEndian(b []byte) (res uint64) {
|
||||
mul := uint64(1)
|
||||
for i := 0; i < len(b); i++ {
|
||||
res += uint64(b[i]) * mul
|
||||
mul *= 256
|
||||
}
|
||||
return res
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue